Recently, with the developments of high-tech industry, manufacturers continuously release different types of high-tech products in the market, such as laptops, tablets or smart phones, etc. In general, those high-tech products operate using power supplied by power adapters. However, although power adapters provided by most manufacturers are similar, those power adapters are incompatible with each other. For example, a power adapter manufactured by a manufacturer is not adapted to products (e.g. laptops or smart phones) manufactured by another manufacturer.
In other words, products manufactured by a manufacturer are only allowed to be charged using power adapters produced by the manufacturer. In this case, not only inconveniences are caused to customers, but also more power adapters are necessarily manufactured as manufacturers continuously release new products. In order to solve the problems of wasting resources caused by different power adapters, a new type of power supply device and interface (Universal Serial Bus Type-C, hereafter “USB Type-C/USB Power Delivery”) is provided for uniformity of power supply ports provided by different manufacturers and equipped with functions of power adapters, so that the wastes of resources and harmful effects on the environment could be reduced. However, during the transition period of promotions of USB Type-C/USB Power Delivery, new power adapters are still continuously produced and consequently the harmful effects on the environment are continuously created.